More than 260 species of birds are found in the varied habitats of Glacier National Park. That is a large number of species for an area so far north. Variable climatic conditions created by the Continental Divide yields a patchwork of aquatic, riparian and terrestrial habitats ideally suited for birds.
Glacier Park is perhaps the best place to see harlequin ducks in the lower 48 states. These "clown ducks", painted in a gray-orange-black-white costume, seem to frolic as they swim and dive in the turbulent water of McDonald Creek. They walk the bottom in search of mollusks and aquatic insects. Their peculiar barking call can often be heard above the roar of rapids when feeding and they emit a squeaking sound during courtship rituals.
Dippers (water ouzels) prefer the same habitat and often may be spotted on a rock midstream "dipping"-- vigorously bobbing up and down. Their long wading legs have feet with no webs so locomotion upstream is provided by thrusting their stubby wings and tail and "flying" underwater. They have clear, retractable nictitating membranes over their eyes and special flaps to close their nostrils. The Dipper's oil glands are ten times as large as most other water birds, and the oil gives them a distinctive rotten fish smell. The oily outer shell of feathers, combined with a thick layer of under-down, gives them the ability to dive under ice during midwinter.
In the old growth forests of the McDonald Creek area, swifts often appear at dusk to feed on hatching insects. They bathe while skimming calm water and splash themselves with their tails; they even mate in flight.
Black swifts and Vaux's swifts eat many insects, but are known more for their nesting habits. Vaux's swifts are colony nesters that use huge hollowed snags in the old growth forest for their roosts and nests. They emerge by the hundreds like bats from a cave at feeding times. Black swifts also nest in colonies -- often in precarious places. They prefer the safety of nests constructed on rock walls behind waterfalls. Both types of swifts have the ability to go into a state of semi-hibernation when food is scarce. Their high metabolism would cause them to starve within a day or two without eating.
At the other end of the altitude spectrum in the alpine tundra, timberline sparrows, rosy finches and white-tailed ptarmigans spend their summers breeding and raising young. Ptarmigans remain there through the winter, molting white to match the snow. They walk on the deep alpine snows with feathered feet, "snowshoes" which increase the surface area of their feet by four times.
During summer, at high elevations near treeline, Clark's nutcrackers thump their wings audibly and squawk loudly. Nutcrackers have developed a unique relationship with whitebark pines which grow in sunny openings near timberline. The birds gather seeds from the pine cones and carry them in their cheek pouches. They bury the seeds a few inches deep in sunny openings. A single nutcracker may place seeds at several hundred locations each summer for future food stores. They find and eat about 70 percent of the seeds they have cached, apparently by remembering each spot. The remaining seeds are placed at the perfect depth to grow new trees. Unfortunately, blister rust, an introduced disease from Asia, has decimated whitebark communities over the last 60 years. This has substantially reduced nutcracker populations and upset the historic seasonal harvesting cycles of grizzlies and other users of the pine nuts. Research on the relationship between nutcrackers and the whitebark pine and restoration of whitebark pine communities are high priorities for park resource managers. However, it is unclear when, or even if, communities will ever be restored to what they have been in the past.